Abstract: Embodiments of an ultrasonic button and methods for using the ultrasonic button are disclosed. In one embodiment, an ultrasonic button may include an ultrasonic transmitter configured to transmit an ultrasonic wave, a piezoelectric receiver layer configured to receive a reflected wave of the ultrasonic wave, a platen layer configured to protect the ultrasonic transmitter and the piezoelectric receiver layer, a first matching layer configured to match an acoustic impedance of the platen layer with an acoustic impedance of ridges of a finger, and an ultrasonic sensor array configured to detect the finger using the reflected wave.

Abstract: A touch sensitive device including a front panel having a touch surface and a back surface opposite the touch surface. The touch sensitive device further includes one or more vibration transducers mounted to the back surface, and a controller electronically connected to the vibration transducer. The controller receives, from the vibration transducer, a vibration signal, extracts feature information corresponding to predetermined features from the vibration signal, determines, based on the feature information, that a touch occurred within a predefined area of the touch surface, and outputs a signal indicating that the touch occurred within the predefined area of the touch surface.

Abstract: A device includes a first microelectromechanical systems (MEMS) transducer, a second MEMS transducer and a summing device. A first dimension of the first MEMS transducer is predefined to configure the first MEMS transducer to have a first resonance frequency. A second dimension of the second MEMS transducer is predefined to configure the second MEMS transducer to have a second resonance frequency different than the first resonance frequency. The summing device is coupled to the first MEMS transducer and the second MEMS transducer and provides an output representing a combination of information from the first MEMS transducer and the second MEMS transducer.

Abstract: Embodiments of an ultrasonic button and methods for using the ultrasonic button are disclosed. In one embodiment, an ultrasonic button may include an ultrasonic transmitter configured to transmit an ultrasonic wave, a piezoelectric receiver layer configured to receive a reflected wave of the ultrasonic wave, a platen layer configured to protect the ultrasonic transmitter and the piezoelectric receiver layer, a first matching layer configured to match an acoustic impedance of the platen layer with an acoustic impedance of ridges of a finger, and an ultrasonic sensor array configured to detect the finger using the reflected wave.